twin cam to toilet

[birdseye]

Interesting - you learn something every day. Must admit I was assuming the common oil supply on cars thinking that the common change in architecture started with the Mini transverse engine implied this to make the engine / gearbox assembly suficiently compact for transverse mounting. Shouldnt make assumptions!

Anyway as I understand it you are saying that the WC clunk into first is simply a minor design issue caused by too much rotation. Wonder if we will end up with short bevel box lives on the earlier bikes being replaced by short gearbox lives on the WC.

Thanks for your comments. Its nice to come acroiss someone on the forum who knows what he's talking about!

 

[MattW]

Anyway as I understand it you are saying that the WC clunk into first is simply a minor design issue caused by too much rotation. Wonder if we will end up with short bevel box lives on the earlier bikes being replaced by short gearbox lives on the WC.

I'm saying it *may* be due to clutch drag causing the input shaft to rotate with too much force when in neutral / between gears. Unsurprisingly BMW don't admit that there's a problem but fitting longer clutch pushrods seems to point towards this. A proper fix would probably require a new clutch or fairly substantial redesign - very unlikely to be applied as a retrofit to earlier bikes but might have already been introduced in 2014 / 2015 bikes. Who knows?...

Thanks for your comments. Its nice to come acroiss someone on the forum who knows what he's talking about!

Thinking I know what I'm talking about - there's your first mistake

There are many more on the forum who know much more than me...

 

[Engineer]

A small amount of drag / overspin is engineered into most constant mesh bike gearboxes. Otherwise it could stop 'between dogs' and refuse to engage. However, getting this drag right is something of a black art and not every box design is successful in this respect.

The previous air-cooled 1200GSs did exactly that, one had to 'drag' the clutch a little to get them into 1st sometimes.